Hi,
It sounds like you have a ground issue. First, check the condition of the battery terminals to make sure they are clean, tight, and free of corrosion. Here is a link you may find helpful:
https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked
If they are good, then I need you to follow the wire or wires from the negative battery terminal and check where they mount to the engine and body of the vehicle. Confirm they are also in good condition.
The specific ground I am questioning is located under the hood on the inner fender. It provides ground direct to the headlamps and the powertrain control module. If the ground is weak, it will likely cause what you are experiencing.
Check that ground first. If possible, run a new ground (in addition to) between the battery negative and the ground location mentioned.
Let me know if that takes care of the problem for you.
Take care,
Joe
See pic below for ground info.
Image (Click to make bigger)
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Wednesday, December 29th, 2021 AT 6:33 PM